Before I even get a chance to speak to Warren Mitchell, who is playing the title role in Visiting Mr Green, I hear complaints about him from the staff at the hotel where he is staying.

I've been told to call him at his hotel promptly at 10am, but I can't get through because he's got the phone off the hook.

The receptionist sighs and says: "He's very odd. He's so rude."

I heed her warning but it doesn't quite prepare me for what is to follow.

For a start, Warren seems confused about using the telephone. The receptionist tells him to hang up so she can put my call through, but he doesn't. When I finally do get through, he then hangs up on me.

For some reason, he fails to see the funny side of this.

"I'm sorry there appears to have been some phone confusion," I say, when I finally manage to get hold of him.

"What are you laughing at?"

"There appears to have been some confusion with the phone, I'm sorry," I say again.

"That's all right," he replies, grumpily, reminding me distinctly of his most famous alter ego, Alf Garnett.

So how are you? I ask.

"Well, I'm exhausted from trying to chase the phone round the apartment."

By now, I'm trying to stop myself from collapsing into giggles but somehow I manage to remain professional.

I steer the conversation towards the play, in which Warren plays an elderly, infirm, crotchety Jewish New York widower.

When Mr Green is almost run over by corporate executive Ross Gardiner (played by David Sturzaker), Ross is ordered to spend the next six months making weekly visits to the old man.

Initially chalk and cheese, a tender bond slowly develops between the two men.

Jeff Baron's comic two-hander first opened in 1996 with veteran film star Eli Wallach in the title role and has since been performed in 37 countries. "Everywhere it's staged the laughs come in the same places, apparently," says Warren.

Aged 81, I ask what compelled Warren to tour the country with this play.

"It's a big part. I get to be on stage most of the time, which I love, and it is extremely well written," he replies, before grumbling about a waiter who has brought him coffee which apparently tastes like "dishwater".

And how do you compare to your character, I plough on.

"He's stubborn, proud and pretty cantankerous. You'll find out I'm pretty cantankerous too, if you keep me away from my coffee much longer."

I take the hint and quickly ask if he can ever imagine retiring from the stage.

"Well, yes, if I'm forced to. If I can't remember my lines and if I fall over the furniture, then I'll have to. I think I'll go and have my coffee now if you'll excuse me."

And with that, he's gone. I'm left pitying the hotel staff and wondering just how much acting will be required for a cantankerous old man to play a cantankerous old man.

  • Starts 7.45pm, tickets £17-£27. Call 08700 606650.